Problem: Ashley starts counting at 50, and she counts by threes. If 50 is the 1st number that Ashley counts. what is the 12th number that she counts?
What is the first number that she counts? $50$ What is the second number that she counts? $\begin{align*}&50 + 3 \\ &= 53\end{align*}$ What is the third number that she counts? $\begin{align*}&50 + 3 + 3 \\ &= 50 + (2 \times 3) \\ &= 56\end{align*}$ What is the 12th number that she counts? $\begin{align*}&50 + (11\times3) \\ &= 50 + 33 \\ &= 83\end{align*}$